74431-52-0Relevant articles and documents
Steroselective hydrolysis of DL-beta-acetylthioisobutyramide catalyzed by genetically engineered E. coli immobilized on Celite 580 in a packed bed bioreactor
Shaw, Shyh-Yu,Chen, Yu-Jen,Ou, Jung-Jung,Ho, Lewis
, p. 1607 - 1613 (2007)
Pseudomonas putida IFO12996 catalyzes the stereoselective hydrolysis of methyl DL-β-acetylthioisobutyramide (DL-ATIA) to form D-β- acetylthioisobutyric acid (DAT), a key intermediate for synthesis of a series of angiotensin converting enzyme inhibitors. The esterase gene of Pseudomonas putida IFO12996 was cloned and expressed in Escherichia coli which was further immobilized and retained on a packed bed bioreactor filled with Celite 580. The packed bed bioreactor was used to conduct the stereoselective hydrolysis of DL-ATIA and to give DAT with a yield of 34.5%, enantiometric excess value of 97% and enantioselectivity value > 150. The optimal pH and temperature for the reaction were 9.0 and 57 °C ～ 67 °C, respectively. The kinetic constants (Km and Vmax) of immobilized cells were found to be 372.5 mM and 285.7 μmol min-1 (g cell)-1, respectively. The immobilized cells retained over 60% of the initial catalytic activity after 5 batch cycles of production. This paper presents a simple, practical and economical process of immobilization of genetically engineered E. coli on a novel packed bed bioreactor for production of DAT.
Organocatalytic enantioselective transient enolate protonation in conjugate addition of thioacetic acid to a-substituted n-acryloyloxazolidinones
Unhale, Rajshekhar A.,Rana, Nirmal K.,Singh, Vinod K.
supporting information, p. 1911 - 1915 (2013/05/23)
Organocatalytic conjugate addition of thioacetic acid to a series of a-substituted N-acryloyloxazolidin-2- ones followed by enantioselective protonation has been studied in the presence of thiourea catalysts derived from cinchona alkaloids. Conjugate addition/protonation adducts have been obtained up to 97% ee and high yields. The methodology could serve as an easy and practical route to the syntheses of useful biologically active molecules.
